I got curious and looked it up in RIA Checkpoint and yes, the estate of a deceased payor ex-spouse can continue to make deductible alimony payments to a surviving recipient ex-spouse if that obligation is written into the divorce decree or other agreement.  The value of the alimony obligation is deducted as a claim against the estate on Form 706 Schedule K.  See below:

Under IRC Sec. 2053, indebtedness or claims that are founded on a “promise or agreement” are deductible only to the extent they were contracted in a bona fide transaction for adequate and full consideration. A transfer of property in satisfaction of spousal marital rights (rights conferred on a surviving spouse by local law upon the death of his or her spouse) is deemed to be made for full and adequate consideration if [IRC Secs. 2043(b)(2) and 2516]:

1. the continued payments are pursuant to a qualifying written agreement under IRC Sec. 2516 as to the parties’ marital and property rights;

2. a final decree of divorce occurs within the three-year period beginning one year before and ending two years after the agreement is entered into; and

3. the property transfer is made to settle marital property rights or to provide a reasonable allowance for the support of the parties’ minor children.

Thus, the continued payment of alimony and child support obligations (or a transfer of property in satisfaction of the obligation) by the decedent’s estate, pursuant to an agreement meeting the above requirements, is deductible as a claim against the estate. The agreement need not be approved by a court so long as the obligation is valid under applicable local law.

Valuing an Alimony Obligation

The valuation of an estate’s obligation to continue payment of alimony after the decedent’s death is determined actuarially based on the life expectancy of the decedent’s spouse. The payments should be valued using the tables issued under IRC Sec. 7520 and a rate equal to 120% of the federal midterm rate (rounded to the nearest .2%) in effect for the month in which the valuation date falls.

Example 13C-2: Valuation of the estate’s obligation to pay alimony.

At the time of Will Brodsky’s death, he was obligated to pay his former wife, Julie, $1,250 per month for the remainder of her life. The obligation to make the payment was pursuant to an agreement entered into one month prior to their divorce and was in exchange for Julie’s relinquishment of her marital property rights. Julie was 64 years and 7 months old at the date of Will’s death and will continue to receive the payments on the first of each month. Using the four-step process for valuing annuities for life, and a Section 7520 rate of 7.4%, the value of the estate’s obligation to pay Julie $1,250 per month for life would be $135,215. Accordingly, the estate would be entitled to deduct this amount as a claim against the estate on Schedule K.

Aznanalyst83 wrote: That is just wrong in certain ways. I really don't want to get married now -_-

I don't want to get too political on these forums, but a combination of laws which are generally overwhelmingly friendly to non-working spouses (still mostly female) and a predominance of man-bad-woman-good (feminist indoctrination) judges make marriage something of a foolhardy institution in this day and age.